Christopher Ferris | df29061 | 2014-01-22 19:21:07 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2014 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
Christopher Ferris | 3a14004 | 2016-06-15 15:49:50 -0700 | [diff] [blame] | 17 | #include <pthread.h> |
Christopher Ferris | 2c43cff | 2015-03-26 19:18:36 -0700 | [diff] [blame] | 18 | #include <stdint.h> |
Dan Albert | ac2fe7e | 2014-05-21 18:21:02 -0700 | [diff] [blame] | 19 | #include <stdlib.h> |
Christopher Ferris | df29061 | 2014-01-22 19:21:07 -0800 | [diff] [blame] | 20 | #include <sys/types.h> |
| 21 | #include <unistd.h> |
| 22 | |
| 23 | #include <backtrace/BacktraceMap.h> |
| 24 | |
| 25 | #include <libunwind.h> |
| 26 | |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 27 | #include "BacktraceLog.h" |
Christopher Ferris | df29061 | 2014-01-22 19:21:07 -0800 | [diff] [blame] | 28 | #include "UnwindMap.h" |
| 29 | |
| 30 | //------------------------------------------------------------------------- |
| 31 | // libunwind has a single shared address space for the current process |
| 32 | // aka local. If multiple maps are created for the current pid, then |
| 33 | // only update the local address space once, and keep a reference count |
| 34 | // of maps using the same map cursor. |
| 35 | //------------------------------------------------------------------------- |
Christopher Ferris | df29061 | 2014-01-22 19:21:07 -0800 | [diff] [blame] | 36 | UnwindMap::UnwindMap(pid_t pid) : BacktraceMap(pid) { |
Christopher Ferris | d4c8843 | 2016-02-05 11:07:12 -0800 | [diff] [blame] | 37 | unw_map_cursor_clear(&map_cursor_); |
Christopher Ferris | df29061 | 2014-01-22 19:21:07 -0800 | [diff] [blame] | 38 | } |
| 39 | |
Christopher Ferris | d4c8843 | 2016-02-05 11:07:12 -0800 | [diff] [blame] | 40 | UnwindMapRemote::UnwindMapRemote(pid_t pid) : UnwindMap(pid) { |
| 41 | } |
| 42 | |
| 43 | UnwindMapRemote::~UnwindMapRemote() { |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 44 | unw_map_cursor_destroy(&map_cursor_); |
| 45 | unw_map_cursor_clear(&map_cursor_); |
Christopher Ferris | df29061 | 2014-01-22 19:21:07 -0800 | [diff] [blame] | 46 | } |
| 47 | |
Christopher Ferris | d4c8843 | 2016-02-05 11:07:12 -0800 | [diff] [blame] | 48 | bool UnwindMapRemote::GenerateMap() { |
Christopher Ferris | df29061 | 2014-01-22 19:21:07 -0800 | [diff] [blame] | 49 | // Use the map_cursor information to construct the BacktraceMap data |
| 50 | // rather than reparsing /proc/self/maps. |
| 51 | unw_map_cursor_reset(&map_cursor_); |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 52 | |
Christopher Ferris | df29061 | 2014-01-22 19:21:07 -0800 | [diff] [blame] | 53 | unw_map_t unw_map; |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 54 | while (unw_map_cursor_get_next(&map_cursor_, &unw_map)) { |
Christopher Ferris | df29061 | 2014-01-22 19:21:07 -0800 | [diff] [blame] | 55 | backtrace_map_t map; |
| 56 | |
| 57 | map.start = unw_map.start; |
| 58 | map.end = unw_map.end; |
Christopher Ferris | af67fb2 | 2015-05-06 12:50:09 -0700 | [diff] [blame] | 59 | map.offset = unw_map.offset; |
Christopher Ferris | 96722b0 | 2017-07-19 14:20:46 -0700 | [diff] [blame^] | 60 | map.load_bias = unw_map.load_base; |
Christopher Ferris | df29061 | 2014-01-22 19:21:07 -0800 | [diff] [blame] | 61 | map.flags = unw_map.flags; |
| 62 | map.name = unw_map.path; |
| 63 | |
| 64 | // The maps are in descending order, but we want them in ascending order. |
| 65 | maps_.push_front(map); |
| 66 | } |
| 67 | |
| 68 | return true; |
| 69 | } |
| 70 | |
Christopher Ferris | d4c8843 | 2016-02-05 11:07:12 -0800 | [diff] [blame] | 71 | bool UnwindMapRemote::Build() { |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 72 | return (unw_map_cursor_create(&map_cursor_, pid_) == 0) && GenerateMap(); |
| 73 | } |
| 74 | |
| 75 | UnwindMapLocal::UnwindMapLocal() : UnwindMap(getpid()), map_created_(false) { |
Christopher Ferris | 3a14004 | 2016-06-15 15:49:50 -0700 | [diff] [blame] | 76 | pthread_rwlock_init(&map_lock_, nullptr); |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 77 | } |
| 78 | |
| 79 | UnwindMapLocal::~UnwindMapLocal() { |
| 80 | if (map_created_) { |
| 81 | unw_map_local_destroy(); |
| 82 | unw_map_cursor_clear(&map_cursor_); |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | bool UnwindMapLocal::GenerateMap() { |
Christopher Ferris | 3a14004 | 2016-06-15 15:49:50 -0700 | [diff] [blame] | 87 | // Lock so that multiple threads cannot modify the maps data at the |
| 88 | // same time. |
| 89 | pthread_rwlock_wrlock(&map_lock_); |
| 90 | |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 91 | // It's possible for the map to be regenerated while this loop is occurring. |
| 92 | // If that happens, get the map again, but only try at most three times |
| 93 | // before giving up. |
Christopher Ferris | 3a14004 | 2016-06-15 15:49:50 -0700 | [diff] [blame] | 94 | bool generated = false; |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 95 | for (int i = 0; i < 3; i++) { |
| 96 | maps_.clear(); |
| 97 | |
Christopher Ferris | d4c8843 | 2016-02-05 11:07:12 -0800 | [diff] [blame] | 98 | // Save the map data retrieved so we can tell if it changes. |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 99 | unw_map_local_cursor_get(&map_cursor_); |
| 100 | |
| 101 | unw_map_t unw_map; |
| 102 | int ret; |
| 103 | while ((ret = unw_map_local_cursor_get_next(&map_cursor_, &unw_map)) > 0) { |
| 104 | backtrace_map_t map; |
| 105 | |
| 106 | map.start = unw_map.start; |
| 107 | map.end = unw_map.end; |
Christopher Ferris | af67fb2 | 2015-05-06 12:50:09 -0700 | [diff] [blame] | 108 | map.offset = unw_map.offset; |
Christopher Ferris | 96722b0 | 2017-07-19 14:20:46 -0700 | [diff] [blame^] | 109 | map.load_bias = unw_map.load_base; |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 110 | map.flags = unw_map.flags; |
| 111 | map.name = unw_map.path; |
| 112 | |
| 113 | free(unw_map.path); |
| 114 | |
| 115 | // The maps are in descending order, but we want them in ascending order. |
| 116 | maps_.push_front(map); |
| 117 | } |
| 118 | // Check to see if the map changed while getting the data. |
| 119 | if (ret != -UNW_EINVAL) { |
Christopher Ferris | 3a14004 | 2016-06-15 15:49:50 -0700 | [diff] [blame] | 120 | generated = true; |
| 121 | break; |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 122 | } |
| 123 | } |
| 124 | |
Christopher Ferris | 3a14004 | 2016-06-15 15:49:50 -0700 | [diff] [blame] | 125 | pthread_rwlock_unlock(&map_lock_); |
| 126 | |
| 127 | if (!generated) { |
| 128 | BACK_LOGW("Unable to generate the map."); |
| 129 | } |
| 130 | return generated; |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 131 | } |
| 132 | |
| 133 | bool UnwindMapLocal::Build() { |
| 134 | return (map_created_ = (unw_map_local_create() == 0)) && GenerateMap();; |
| 135 | } |
| 136 | |
Christopher Ferris | 12385e3 | 2015-02-06 13:22:01 -0800 | [diff] [blame] | 137 | void UnwindMapLocal::FillIn(uintptr_t addr, backtrace_map_t* map) { |
| 138 | BacktraceMap::FillIn(addr, map); |
| 139 | if (!IsValid(*map)) { |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 140 | // Check to see if the underlying map changed and regenerate the map |
| 141 | // if it did. |
| 142 | if (unw_map_local_cursor_valid(&map_cursor_) < 0) { |
| 143 | if (GenerateMap()) { |
Christopher Ferris | 12385e3 | 2015-02-06 13:22:01 -0800 | [diff] [blame] | 144 | BacktraceMap::FillIn(addr, map); |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 145 | } |
| 146 | } |
| 147 | } |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 148 | } |
| 149 | |
Christopher Ferris | df29061 | 2014-01-22 19:21:07 -0800 | [diff] [blame] | 150 | //------------------------------------------------------------------------- |
| 151 | // BacktraceMap create function. |
| 152 | //------------------------------------------------------------------------- |
Christopher Ferris | dda47b7 | 2014-08-04 17:08:46 -0700 | [diff] [blame] | 153 | BacktraceMap* BacktraceMap::Create(pid_t pid, bool uncached) { |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 154 | BacktraceMap* map; |
Christopher Ferris | dda47b7 | 2014-08-04 17:08:46 -0700 | [diff] [blame] | 155 | |
| 156 | if (uncached) { |
| 157 | // Force use of the base class to parse the maps when this call is made. |
| 158 | map = new BacktraceMap(pid); |
| 159 | } else if (pid == getpid()) { |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 160 | map = new UnwindMapLocal(); |
| 161 | } else { |
Christopher Ferris | d4c8843 | 2016-02-05 11:07:12 -0800 | [diff] [blame] | 162 | map = new UnwindMapRemote(pid); |
Christopher Ferris | e296091 | 2014-03-07 19:42:19 -0800 | [diff] [blame] | 163 | } |
Christopher Ferris | df29061 | 2014-01-22 19:21:07 -0800 | [diff] [blame] | 164 | if (!map->Build()) { |
| 165 | delete map; |
Christopher Ferris | 2c43cff | 2015-03-26 19:18:36 -0700 | [diff] [blame] | 166 | return nullptr; |
Christopher Ferris | df29061 | 2014-01-22 19:21:07 -0800 | [diff] [blame] | 167 | } |
| 168 | return map; |
| 169 | } |